The purpose of this proposed project is to systematically investigate contributions of family interactions to two facets of adolescent psychosocial development: adolescent ego development and adolescent ego processes. Early adolescent subjects and their parents are studied over a four year period in terms of individual psychosocial development and developmentally relevant family process dimensions. Theoretical perspectives from developmental psychology and family process literature underlie the hypotheses, questions, and assessment strategies embedded in six proposed studies. The subjects are 365 Caucasian upper-middle and upper-class adolescents and their parents. The adolescents enter the study in early adolescence (mean age = 14.6) and continue over the next four years. This is a multi-method study. Annual measures include: individual ego development tests (to adolescents and each parent); an extensive clinical-research interview, coded for coping and defense processes; an audio-taped Family Interaction Task, and intelligence tests. The transcribed family discussions are objectively coded using our newly constructed Constraining and Enabling Coding System (CECS) and assessment scales for family power structure and rigidity/flexibility. Hypotheses and questions are investigated through six studies using multivariate statistical procedures. These studies explore relationships between family processes and adolescent development in terms of stage change (e.g. progression, arrest) as well as ego process shift. These studies have significant implications for understanding growth-enhancing and growth-retarding features of family experience, together with the family's impact upon adolescent psychosocial adaptive processes.